The present invention relates to farm equipment and, more particularly, to an adjustment mechanism having particular utility for quickly and easily adjusting the position of one part of a tool, such as a cleaning tine or gauge wheel of a coulter assembly, relative to another part of the tool, such as the coulter blade of the assembly. The invention is especially well-suited for large tillage or planting machines having many separate furrow opening units across the width of the machine, all of which must be uniformly adjusted.
Mechanisms and devices for adjusting and releasably retaining various components of farm equipment tools in selected positions of adjustment are well known in the art. However, many such mechanisms require the use of hand tools for making the adjustments, and many are rather tedious and time-consuming to use. Furthermore, many are not particularly precise.
Large, wide tillage and planting machines present particular challenges because they may be provided with fifty or more separate opener units that must all be maintained at the same setting. For example, if a slightly different running depth is desired for the coulter blades or other furrow opening devices of the machine, the gauge wheel of each and every opener on the machine must be adjusted before the machine can begin operations. Moreover, with conventional adjustment devices, it may be difficult to assure that each opener is set to the same depth.
The present invention provides an adjustment mechanism that can be operated quickly and easily without the need for hand tools. It also provides for relatively precise adjustments without sacrificing structural strength and sturdiness, which can be especially important in those applications where the device may be subjected to harsh conditions and heavy loading such as found in tillage and planting operations.
In a preferred embodiment of the invention a stationary part of the mechanism supports a movable part for pivotal adjustment about an axis of adjustment. A series of alternate teeth and notches on one of the parts are arranged in an arcuate pattern about the axis of adjustment, while a pair of arcuately spaced latching bars on the other part are adapted for independent movement into and out of engagement with the teeth and notches. The spacing between the latching bars is such that when either of the bars is in registration with a notch, the other bar is in registration with a tooth. Thus, by spring-loading both bars, one of them can be seated within a notch to retain the movable member in a selected position of adjustment while the other is maintained in a standby position abutting the outer end of a neighboring tooth. To change the position of the member by one increment, the seated bar is withdrawn from the notch and held against reinsertion, which releases the movable member. When the movable member is indexed one increment, the bar in the standby position snaps down into a notch now brought into registration with it and reestablishes a latched condition in the new position of adjustment. The previously latched bar can now be released to reside in a standby position spring-biased against the outer end of a tooth.
In an especially preferred embodiment, the teeth and notches are on the movable member, while the spring-loaded latching bars are on the stationary member. Further, a single actuating lever is connected to the two bars in such a manner as to facilitate withdrawal of a seated bar from a notch and to temporarily retain it in a withdrawn condition until the movable member has been indexed by one increment and the withdrawn bar is now retained in the standby position by the outer end of a tooth. The connection of the lever to the bars is in the nature of a pair of separate fulcrum connections that enable the lever to fulcrum about alternate ones of the bars in a pumping-like lift and lower action as the movable member is adjusted through successive increments.
The invention may be advantageously incorporated into a tillage or planting machine where many separate, individual opener assemblies across the width of the machine are provided. The movable member on each opener assembly may have a cleaning tine associated with it whose position relative to a coulter blade may need to be adjusted to provide optimum field operations. Alternatively, the movable member may have a gauge wheel associated with it that determines the depth of penetration of the coulter blade into the soil such that adjustment of the gauge wheel relative to the coulter blade correspondingly adjusts the depth of penetration. Furrow closing wheels and other structures requiring adjustment could alternatively be associated with the movable member.